Method for oscillating drilling



Aug. 14, 1962 w. K. J. HERBOLD METHOD FOR OSCILLATING DRILLING 4Sheets-Sheet 1 Filed Dec. 26, 1956 n r... r fi FIG. 3

INVENTOR. WOLFGANG KONRAD JACOB HERBOLD FIG.2

ATTORNEY Aug. 14, 1962 w. K. J. HERBOLD METHOD FOR OSCILLATING DRILLING4 Sheets-Sheet 2 Filed Dec. 26, 1956 INVEN TOR. WOLFGANG KONRAD JACOBHERBOLD ATTORNEY Aug. 14, 1962 w. K. J. HERBOLD METHOD FOR OSCILLATINGDRILLING 4 Sheets-Sheet 3 Filed Dec. 26, 1956 ATTORNEY Aug. 14, 1962 w.K. J. HERBOLD METHOD FOR OSCILLATING DRILLING 4 Sheets-Sheet 4 FiledDec. 26, 1956 FIG.

FIG. I2

3,049,185 METHGD FOR OSCILLATING DRHJLHQG Wolfgang Konrad JacobHer-bold, Kierdorf, Post Lechenich, Germany, assignor of one-half toPaul 0.

Tobeler, doing business under the name of Trans- Oceanic, Los Angeles,Calif.

Filed Dec. 26, 1956, Ser. No. 630,495 9 Claims. (Cl. 17S19) When holesare drilled into the ground, whether accomplished by hammer blows orthrough rotary drilling, the boring always produces a hole having adiameter which is considerably larger than the poles or drill rods whichoperate the boring tool. If the hole is not self supporting, aprotective tubing must be inserted to prevent cave-ins. This protectivetubing usually is not utilized as a part of the drilling equipment andits sole purpose is protection against the collapse of the materialimmediately surrounding the drill hole.

For horizontal drilling in light or sandy soil, methods are known inwhich the drill tubing is embedded in the soil, making contact therewithwith its whole outer surface in such a manner that, through a shuttlemotion by means of hydraulic drives which are capable of producingconsiderable force, the tubing is advanced in the direction of thedrilling to overcome the very great friction between the soil and thetubing. However, the operational range of these methods is limited bythe excessive resistance of the friction.

The present invention provides means and method for drilling, utilizinga drill operating mechanism in which the drill rod and casing arecombined as a unit so that the rod drives the casing within the boredhole. The means to accomplish the work performable by the presentinvention are, in part, disclosed in my United States Patent No.2,730,176, which relates to a method for the recovery of imbedded tubingby rolling oscillation. In accordance with that patent, the imbeddedtubes are subjected to oscillating forces, acting across the tube axes,and to rotary motions. According to the present invention, a drill rodand roller disks secured on said rod are caused to rotate in contactwith the internal surface of the drill tubing to produce centrifugalforces perpendicular to the main longtudinal axis of said drill tubing,which also serves as the protective tubing in the hole.

During the rotating and rolling process of the drill rod, it is held inan eccentric position relative to the axis of the drill tubing. Thedrill tubing rotates on enlarged diameter rollers on the drill rod andwhich in turn roll along the inner wall of the drill tube. The latterrotates on its own axis in the direction opposite to that of thecirculating centrifugal force because the drill tubing itself rollsabout the wall of the bore hole effected by the circulating centrifugalforce. Thus, the drill tubing is driven immediately within the hole tobe drilled and gets its rotating drive at the inner wall of the borehole and not from a rotary table above the ground, and advances by itsown weight as it would in conventional rotary drilling.

In the present method the resistance of friction between the exteriorsurface of the drill tubing and the soil is practically whollyeliminated in the direction of the advance of the drilling so that theweight of the equipment for vertical drilling, or the force required forthe advance in horizontal drilling, is exerted to its full extent to thebottom or advanced drill point of the soil and, therefore, in favor ofthe advance of the drill. It is known from the theory of friction, thatthe latter is always opposed to the direction of the advancing force.That is, to move a mass along a support offering friction, the forcerequired to move the mass must be at 3,fi49,l Patented Aug. 14, 1962least equal to the coefiicient of friction multiplied by the mass or nomotion will result. If the force is of that required magnitude, that is,the mass is in motion, an insignificantly small force in the directionvertical to the main force will cause a component of motion in thedirection across the direction of the main force. For this motion acrossthe direction of the main force, no minimum force is required; however,each force across the direction of the main force, no matter how small,creates a motion, the coefiicient of friction along the cross directionbeing practically zero.

In conventional rotating drilling employing a tube mechanism forentering the soil, the identical teachings apply; however, theresistance of friction to be overcome through the rotation of the toolsoon becomes prohibitive at worthwhile depths. In accordance with thepresent invention, however, only the dynamic friction, which isconsiderably smaller, needs to be overcome. In addition according to thepresent invention, the soil is continuously removed by means of therotation and caked so that the transmission remains loose within thesoil.

The method of drilling provided by the present invention is superiorover known methods in the art in that only a single, relatively narrowtube train or drill rod transmission within a drill tubing is requiredto attain a drilled hole equipped with a protective tubing down to thefinal depth of the hole. 'Ihese tubings never seat inside the soil andcan be loosened, even after long periods, either for the purpose ofcontinued boring or for the removal of the tubing. By employing thepresent invention it is now possible to drill effectively a smalldiameter hole into light soil in a horizontal direction for longdistances because the resistances of friction are eliminated in thedirection of the drilling so as to prevent the seating of the drill andtransmission tubing.

It is an object of the present invention to provide a new and improvedmethod and means of drilling.

It is a principal object of the present invention to provide a methodand means for vertical and horizontal drilling in which a protectivedrill tubing, forming the drilled hole, is caused to roll along saidhole surface by means of rotating centrifugal forces directed across thelongitudinal axis of the tubing.

It is a further object of the present invention to provide a method ofdrilling in which the resistance between the outside of the drive tubingand the soil is practically wholly eliminated in the direction of theadvance of the drilling so that the weight of the equipment is exertedto its full extent in favor of the advance of the drill.

Other objects of invention will become apparent from the followingdescription taken in connection with the accompanying drawings, in whichFIG. 1 is a partially cross sectional view of a motor driven drill rodtransmission magnetically attracted to the interior surface of the drilltubing which has a closed advancing end;

FIG. 2 is a view of the present invention in which the advancing end ofthe drill tubing is detachable;

FIGS. 3 and 4 show embodiments of the present invention by whichperiodic core samples may be extracted;

FIG. 5 is a view of the present invention by which the soil loosened bythe drill tip may be forced from the hole through the drill rod;

FIGS. 6 and 7 illustrate an embodiment of the present invention by whicha permanent filter may be inserted with the drill tubing;

FIG. 8 is an embodiment of the present invention employing anon-magnetic drill rod transmission linkage;

FIG. 9 shows another embodiment for the creation of rotating crossforces according to the present invention;

FIG. 10 is a cross sectional view taken along the line 1ll-10 of FIG. 9;

FIG. 11 illustrates an embodiment of the present invention in which anonmagnetic eccentric Weight is used to create centrifugal force acrossthe longitudinal axis of a hard surface drill;

FIG. 12. shows an embodiment of the invention in which eccentric camsare caused to produce a circulating elastic bend;

FIG. 13 is an embodiment of the present invention in which a curved corerod is used within the hollow drill tubing also causing a circulatingelastic bend;

FIG. 14 is an embodiment of the invention which develops a rotatingkinking process to cause a rotary motion of the drill tubing;

FIG. 15 is an embodiment of the invention in which a high speed motorwithin a case, having a core tube, drives an eccentric Weight to developcentrifugal force to cause the rotation of the drill tubing; and

FIG. 16 shows a train of transmission rods assembled from a number ofthe elements of the embodiments shown in FIG. 13.

Referring to FIG. 1, cylindrical hollow tubing or drill tubing 1, havinga closed tapered point 1a at its low or advancing end, is extending intoa bored hole 6a in soil 6. In the interior of tubing 1 is an innertransmission linkage comprising a drill rod 2 having enlarged diameterrollers 3 spaced and fixed thereon to rotate therewith. Rollers or disks3 are attracted magnetically to the inside wall of tubing 1 but are freeto roll along said Wall. In this embodiment of the invention tubing 1 ismagnetically attractable and disks 3 are permanent magnets. Disks 3would also function in the same manner having a conventionalelectromagnet built therein for which direct current for energizing themagnet could be supplied through a pair of lead-in wires wound aroundrod 2 or supplied by having a positive lead-in wire Wound around the rodwith the negative wire of the magnet grounded to pipe 1 in aconventional manner. The lead-in wires could also be inserted inside rod2.

Through rotation of rod 2 'by means of universal joints 4 and connectinglink 4a, as driven by motor 5, the disk magnets 3 roll along the insidesurface of tubing 1, eccentric with respect to the latters longitudinalaxis. The drill rod 2 and the magnetized disks 3 rotate on their owncoincident axes with the same speed as motor 5, in the same direction,but their mass axis '(the same as the latter in symmetrical rods anddisks, as shown), circulates or rolls with the speed according to theratio of d/s with respect to the motor speed around the axis of drilltubing 1, where d is the diameter of rollers 3 and s is the play of therollers 3 inside of tube 1. That is, d plus s are equal to the insidediameter of tube 1. The roll of the drill rod and of the disks is in theopposite direction of their rotation and this thereby effects thecentrifugal force in the direction indicated by the arrow, located inthe approximate center of FIG. 1, extending to the left from tubing 1.This may be explained in that the circumference of the inner wall of thedrill tubing is 11' (d-I-s), and that the circumference of disks 3 is1rd. Thus, after one complete rotation of the disks on their axes whilein contact with the inner wall of the drill tube, for example, to theleft in FIG. 1, the drill rod and disks have been rolled around theirown axes to the right the following distance:

1r(d+S) 1rd d which equals Therefore, one rotation of the drill rodaround its own axis to the right corresponds with d/s rotations of themotor, rod, and disks to the left.

As the drill tubing is forced by the aforesaid centrifugal force againstthe wall of the bore hole, it rotates slowly on its own axis in the samedirection as the rod but in the opposite direction of the rotation ofthe points of contact of the centrifugal force made by the drill tube onthe 'bore hole so that the ratio of the distance traveled by the drilltubing to that of the points of contact of the centrifugal force iswhere d is the outside diameter of the drill tube and s is the distancefrom the exterior of the tube 1 to the surface of the bored hole, d +sbeing equal to the diameter of bored hole 6a. Thus, the drill tubingrotates about its own axis in the same direction as motor 5 at a ratioof d/sXs d with respect to the speed of the motor. However, the speed ofthe drill tubing depends in part upon the compressibility of the soil.The expression circulating or rotating centrifugal force refers to therotation of the points of contact where the rollers exert thecentrifugal force against the drill tubing. Thus, as the disks roll onthe drill tubing, the points of contact where the centrifugal force iseffected, also rotate.

Motor 5 and tubing 1 thereby rotate in the same direction and thetapered point 1a propels itself into the soil, advancing therein by itsown weight or through an additional weight applied thereto.Concurrently, the transmission linkage, drill rod 2 and disk -3, and themotor are also advanced in the direction of the drilling. In thisoperation, the soil is, as in a ramming process, repelled and due to thevibration created, its natural density increases, thus yieldingadditional space externally of tube 1. Thus, according to the presentinvention, the forces required to repel the soil are considerably lessthan in a ramming process, and in addition, the increase of thesurrounding soil density provides considerable advantage in makingfoundations.

Motor 5 may be suspended from a cable or a typical idrilling rod, notshown, as may be secured to a conventional drilling tower. The length oftubing 1, of course, is dependent upon the depth of the hole and motor 5may be lowered in the same linear relationship, as shown in FIG. 1, intothe hole, as it is made so that the actual drilling forces are developedwithin the hole and not in a conventional way in a drilling tower. Motor5 may typically be driven by electricity, water or air. As indicated,the motor should have a diameter smaller than that of the insidediameter of the tubing if it is to be lowered therein as the drillingprogresses.

This embodiment of the invention is of particular merit in theinstallation of pile foundation. As shown in FIG. 2, the tapered point11a at the bottom of drill tubing 11 is detachable. That is, after tip11a has reached its final depth, the drill rod may be withdrawn and apreformed concrete pile may be inserted into the drill tubing, or mixedliquid concrete may be poured therein to surround the usual steelreinforcements. Thereafter, tubing 11 may be withdrawn and the detachedtip Illa remains in the soil.

In FIG. 3, an embodiment of the invention is shown by which periodicextraction of cores is possible. For this purpose generally cylindricaldrill tubing 21, similar to tubing 1 in FIG. 1, has an open lower,tapered end 21a and has a shoulder 27 Within the tubing adjacent theopen end 25a. In the same manner, as described'in reference to FIG. 1,the transmission linkage composed of a drill rod 22 and spaced magneticdisks 23, being magnetically attracted to tubing 21, develop acentrifugal force in the direction of the arrow to cause the rotation oftubing 21. At the lower end of drill rod 2 are, typically, universaljoints 24 connected by a link 24a and the core receiving member 25having its lower end 25a open in the direction of drilling. The corereceiving member is filled as the drill tubing 21 advances into the holeand may be withdrawn at any time during the drilling process by removingthe drill rod 22. If it is desired, a flexible shaft may be used insteadof the universal joints and the connecting links.

In FIG. 4, another type of core receiving member 35 having an open end35a is shown. In this embodiment, the drill tubing 31 is open ended andis shown in soil 36 having formed a hole 36a therein. Core receivingmember 35 will penetrate farther, as shown, forming drilled hole 36b,This arrangement is not intended for continuous core drilling, but onlyfor the occasional taking of a test core. Drill rod 32, forming thetransmission linkage with magnet disks 33, being magnetically attractedto tubing 31 and being driven by a motor not shown, has caused theadvancement of drill tubing 31 into soil 36 and the advancement of corereceiver 35 by means of connecting link 34a, which joins the drill rodand the core receiver by universal joints 34.

In FIG. 5 is shown another embodiment of the present invention in whichdrill tubing 41 has a tapered tip 41a, said tip having an open end 41b.The transmission linkage, which may be driven by a motor as shown inFIG. 1, is comprised of drill rod 42 and magnetic disks 43 spacedthereon and being magnetically attracted to drill tubing 41. Drill rod45 is hollow and has a passage 45 therein, which extends through aflexible portion 42a of the rod. Flexible rod portion 42a extendsthrough gland 47 in head 49 on tubing 41, said tubing 41 being shown tohave entered soil 46. This modification of the present invention permitsthe removal of the loosened soil through passage 45 in drill tubing 42as the drilling progresses. Compressed air or other fluid pressure maybe supplied through fitting 48 so as to flow into tubing 41 around disks43 and rod 42 return above or out of the ground through bore 45,carrying with it the soil that has loosened by drill tip 41a and forcedinto the opening 41b therein. If water is used for this process, it maybe drawn from the water table in the ground. For the drilling processproper, however, no water is required and this is of utmost importancein areas suffering from water shortage.

When drilling for water and using compressed air to lift the loosenedsoil through a bore, as 45 in rod 42, the presence of water is indicatedgenerally by its flowing upward through the tubing. By the insertion ofa slotted filter tube over the drill tubing and slidably engagedtherewith, it is possible to combine test boring for water with theactual drilling process by means of the present invention. The filtertube may be slotted so as to have the efiect of the spring in FIG. 7. Inthis case, however, the drill tubing would not be slotted as it would beintended to withdraw it leaving the filter in place. The formation of abed of natural gravel packing around the filter will be aidedeffectively through the vibratory motions from the transmission linkage.If water is found in sufficient quantity and of adequate quality and, ifthe ejected soil indicates that adequately large grain is present toform a natural gravel packing, the drill tubing together with the innertransmission linkage may be withdrawn, while under vibration from therotating motions and while still carrying the water from wtihin thefilter which may be left in the drilled hole, as held there by thepacking gravel. Afterwards, a sump pump may be installed if necessary.If no satisfactory conditions result, the filter tubing may then bepulled along with the drill tubing likewise under vibration, andrecovered. The aforementioned use of the filter tubing may be employedfor horizontal boring as well a the vertical, thus allowing, inaccordance with the invention, for example, for drainage of sandy slopesand rises created in above surface mining for lignite by horizontaldrilling and its accompanying subsequent solidification of thesurrounding soil.

In place of a filter tubing, a closely Wound coil spring may be employedaround the drill tubing. This is illustrated in FIGS. 6 and 7, Where thecylindrical tubing 51 has holes or slots '55 through its cylindricalsurface. Tubing 51 has a detachable pointed tip 51a and is shown with aportion of transmission linkage of the present in- 6 vention havingmagnetic disks 53 on drill rod 52, said disks being magneticallyattracted to the internal cylindrical surface of tube 51. Around thecylindrical surface of tip 51a and slotted portion of tube 51 is tightlywound a coil spring 54, as shown in FIG. 6. Flange 56 on tubing 51serves to hold spring 54 in tight compression, the other end of saidspring being secured to tip 51a. During the drilling process, the springis pushed forward by flange 56 and remains tightly closed. As soon asthe intended length of the bore has been reached, the rod 52 is lowereda short distance while drill 51 is not lowered. This pushes tip 51adownward and the coils of spring 54; open evenly to form a helicalfilter or screen over slots 55 as shown in FIG. 7. Gravel 58 entersbetween the coils of the spring, as shown, and precludes its contractionor further compression.

Referring to FIG. 8, an embodiment of the invention in partialcross-section is shown in which a nonmagnetic inner transmission linkagefor the generation of rotating cross-forces is illustrated. In the drilltubing 61, similar to that in FIG. 1, having a tapered tip 61a isprovided an inner linkage composed of a hollow drill rod 62 on which arespaced, rotatable transmission rollers or cams 63 which transfer thecirculating centrifugal forces caused by the eccentric weights 64 fixedon drill rod 62. The eccentric weights 64, between rollers 63, havetheir eccentricity positioned in the same direction and are formed ofsleevings having the front or side thereof removed, leaving a cutawayportion 65. Drill tubing 62 is caused to rotate by a motor, not shown,as illustrated in FIG. 1, and rollers 63 transmit centrifugal forces todrill tubing 61 while rolling on the inner surface thereof. The rollers63 are, in effect, the transmission bearings for the mass eccentricdrill rod 62. In other words, although rollers 63 rotate on and areconcentric to drill rod 62, they are forced against the inner surface oftubing 61 by the rotation of the eccentric weights 64 and are incontinuous contact with said surface at the point where the resultingforce from the eccentric weights is directed. In this embodiment thereis no up-gearing or speeding up, as occurs with the magneticallyattracted rollers, of the inner linkage, and the directions of rotationand of the cross-forces motion are the same. It should be noted that anessential difference exists when the rotating centrifugal force isproduced, as in FIGS. 1-6, by rolling magnets or as in FIGS. 815, byeccentric nonmagnetic weights and a rotating flexible, bending tube. Inthe first case, the centrifugal force runs contrary to the direction ofrotation of the motor and a gearing in relation to d/s occurs. That is,when s is small in comparison with d the rotation is tip-geared. In thesecond case, the direction of rotation of the motor and rotatingcentrifugal force or elastic bending tube, as in FIGS. 8, 9, 11-15, isthe same and no gearing occurs. Further, the slow rotation of the drilltube and of the rotating centrifugal force are always in oppositedirections and drill tube 61 rotates in the opposite direction to drillrod 62, in FIG. 8, for example.

Referring to FIGS. 9 and 10, there is illustrated another modificationfor the creation of rotating cross-forces according to the presentinvention. Within the cylindrical drill tubing 71, having a closedtapered point, an eccentric rod or tube 72 is provided, embedded, for aconsiderable length within a core 76 which may be made of a nonmetallicor of some plastic material. The transmission assembly formed With rod72 and core 76 is rotatable within tubing 71 and is under a slip fittherein. Rod 72 is shown connected by means of universal joint 74 toshaft of motor 75 which may be suspended from a crane or a conventionaldrilling tower. As core 76 is rotated within tubing 71 it serves as ajournal for the entire transmission of said cross-forces.

In the drilling of solid rock, it is not necessary to subject the wholedrill tubing to the rotating cross-forces because the soil around thedrill hole does not need to be repelled. That is, it suflices to preparethe lower or near end of the drill hole properly. FIG. 11 illustrates anembodiment of the invention for use in drilling rock or other hardmaterials. Drill tubing 81 is shown in cross section in bored hole 86and has an enlarged diameter cylindrical portion 81a. At the forward orlower end of portion 810 is a plane surface having cutting edges to forma cutting bit 91. Within the enlarged diameter portion 81a, a more orless oblong eccentric weight 83 is mounted on drill shaft or rod 82 forrotation within ball bearing 89 to subject tube portion 81a to therotating cross-forces. Weight 83 is driven rotatably by a high speedmotor 85, shown to be enclosed, said motor may be driven by compressedair or electricity. The cutting bit may be of tool steel or cuttingdiamonds and has a passage 90 therein which extends through rod 82 intothe motor portion. If the motor is air driven, for example, the exhaustair may be fed into passage 90 to supply a rinse means to the cuttingsurface of the bit. If the motor should be driven by electricity, otherpassage means may be made available through tube 81a to supply water orair to the aforesaid cutting surface. The entire drilling apparatus maybe suspended by a cable through loop 88 and if the motor is driven byair, the air may be supplied through a supply connection 87. Likewise,if the drive is electric, wires may be connected to the motor through afitting similar to '87.

The advantage resulting from this embodiment are, first, that high speedlightweight motors or drives may be used because the down gearing ofreduction in rotation speed of the drill tubing is effected through therolling process within the soil and, second, that all points on theplane face of bit 91 move at the same speed, resulting in equal wear toall the cutting points. In conventional drilling, the rotational speedat the center of the drill is zero and is considerable along theperiphery, resulting in fast wear of the cutting edges located along theouter zones.

The embodiment shown in FIG. 11 may also be used for metals, Wood or thelike, to countersink or plane. The rolling motion of the hollow tubing81 and 81a within a drill hole may also be accomplished if thetransmission link is flexed elastically or slightly kinked as may bemade possible by application of a universal joint, the flexed or kinkedportion being rotated rapidly.

Another embodiment of the invention is shown in FIG. 12 in which threeeccentric cams 103 are fixed and spaced upon an essentially rigidrotatably driven rod 102 Within hollow tubing 101, having a tapered tip101a. The rotation of the cams cause a bending effect upon the hollowtubing which rolls as it enters the soil and forms the bore hole. Inthis operation, rod 102 flexes too; this, however, has no importance inthe operation and the flexing movement of the aforesaid rod is not shownin the drawing. By means of the rotating deflection, the hollow tubing101 rolls about the lateral surface of the drill hole and thus, turnsslowly also about its own axis. The effect is identical to that causedby the centrifugal force drive through the built-in masses. The forcesin this embodiment, however, do not depend on the rotational speed ofthe drive as the deflection merely depends on the physical dimensionsand not on the rotational speed. This device, therefore, permits the useof comparatively low driving speeds.

The principle shown in the device in FIG. 12 may be more directlyapplied in the embodiment illustrated in FIG. 13 by the insertion of acurved inner rod 112 in the rolling hollow tubing 111, as shown in soil106, the motor to drive rod 112 not being shown. The .curved inner rod112 flexes the surrounding hollow tubing 111 elastically. The flexing,as shown in FIGS. 12 and 13, is somewhat exaggerated, the true extent ofthe flexing being that as found possible in typical steel tubing inwells. In this device the hollow tubing may be also curved and if thetwo curvatures register, the maximum total deflection results; if therotatably driven inner rod or linkage has a curvature opposed to that ofthe hollow tubing, a straight combination will result and the rollinghollow tubing will then, in rapid succession, become curved andstraight, respectively. The elastic deflection likewise ro tates but itis, however, larger in the direction of the curvature of the rolling rodthan in the direction perpendicular to it. Depending upon a selection ofthe curvatures of the inner and outer elements and their moduli ofinertia, the various effects can be accomplished. It is also possible touse a hollow inner linkage, having flutes on its outer surface, ifflushing is desired during the drilling process as is described relativeto FIG. 5.

A long train of transmission rods 112, shown in FIG. 16, assembled froma number of such curved elements shown in FIG. 13, will provide arotating and winding motion and will roll slowly rotating itself aboutthe sur rounding soil. The long train of links, formed by drill tubing11 and 11a and held together by coupling 113, may be provided withhelical flutes 114 on the exterior thereof so as to cause its ownadvance in the direction of V the drilling. In horizontal boring, thedrilling and rolling links work themselves farther into theto-be-drilled hole thus minimizing or even precluding the application ofback pressure. This embodiment excels through its simplicity and thelubrication of the inner transmission within the outer tubing can bereadily accomplished by simply periodically forcing the greases or oilthrough a long aperture in one of the bearing surfaces.

In FIG. 14 there is a modification of the present invention in which thecore cutter tubing 126 receives its drive from the ball and socket joint124 at the cranked lower end of motor driven drill rod 122, said rodbeing held in a central position in drill tubing 121 by spacer 123. Theball and socket joint 124 does not transmit a torque from drill rod 122through the shaft of core cutter 126, but it does transmit a conicalmovement to the axis of the core cutter with respect to the axis of thedrill tubing. By this movement, the path of a cone is generated, saidcone having its apex in the center of the ball in the joint 124, havingits base formed on the roller element 125 at the top of the core cuttertube, and in the same movement, roller 125 effects a circulatingmovement in the lower part of drill tubing 121. As a result of this,core cutting tube 126, as well as roller block 125, rolls about thewalls of the drilled hole and both carry out a slow rotary motion aboutthe longitudinal axis of the drill tubing.

The present invention further permits the placing of the drive meansimmediately at the point of action and permits the transmission of theenergy required for drilling by electrical, compressed air or otherfluids by means of cables or hoses, all this also being applicable tohorizontal drilling. FIG. 15 illustrates such a modification of thepresent invention. Within the tubular envelope or drill tubing 131 is ahigh speed motor 134 arranged to drive an eccentric weight 133, saidmotor being electrical or fluid driven. Drill tube 131 may be suspendedby a hose, tube or cable 141 which is secured to swivel joint 14% so asto permit the rotation of tube 131 with respect to the holding means141. Eccentric Weight 133 is connected to motor 134 by shaft 137 whichrotates in ball bearings 138 as does shaft 139 at the other end of saidweight. Core tubing is secured to tubing 131 and rotates therewith. Thecore tubing here is shown for example only and would not be attached forgeneral use. Ordinarily, a pointed drilling tip would be employed, asshown in FIG. 13. By means of the centrifugal force developed throughthe high speed rotation of eccentric weight 133, the tubular envelope131 rolls on the surface of the drill hole and rotates slowly about thelongitudinal axis. By means of helical flutes provided along the outersurface of the tubular envelope, this automatic boring tool will advanceon its own in the direction of the drilling without requiring a backupforce and is capable of pulling the hose or cable with it, dependingupon whether the motor is fiuid or electrically driven. The cable orhose connection is made through the swiveled head to preclude anyundesirable twisting.

The present invention provides a number of advantages in its variousembodiments. These include high speed drives with which a great speedreduction can be made and the generation of large torques Within thedrill hole without the need of rugged transmissions. It further providesdrilling means in which it is impossible to jam the drilling toolbecause of the absence of friction and at the same time obtain a fullyprotected drill hole. Further, the drilling is possible in a minimumdiameter hole from start to finish in sandy soils where the densitythereof is increased by means of the continuous vibration whichsimultaneously causes the repulsion of the surrounding soil. It furtherprovides a method by which dry and damp soil and Water may be flushedfrom the hole equally effectively by air and provides a device in whichthe employment of a filter is possible along with the actual drillingoperation.

Although the various embodiments of this invention differ in somerespects, they are all based on the same basic principle, and that is,that the drill linkage in whole or in part, a self-advancing drillingtool, is forced against the surface of the drilled hole as the drilltubing rotates and rolls along said surface.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample only and is not to be taken by Way of limitation, the spirit andscope of this invention being limited only by the terms of the appendedclaims.

I claim:

1. A method for drilling comprising introducing combined protective anddrill tubing into the material being drilled, inserting means Withinsaid tubing adapted to rotate on the interior surface of said tubing toprovide rotating centrifugal forces across the longitudinal axis of saidtubing, rotating said means to create said forces, and rotating saidtubing in said hole being drilled against the surface thereof.

2. A method for drilling a bore hole comprising introducing combinedprotective and drill tubing into the material to be drilled, insertinginto said drill tubing rotatable eccentric means adapted to roll on theinterior surface of said drill tubing, rotating said eccentric means onsaid interior surface, and rotating said tubing in said hole beingdrilled against the surface thereof.

3. A method for drilling a bore hole comprising introducing combinedprotective and drill tubing into the material being drilled, inserting adrill rod longitudinally into said drill tubing positioned adjacent theadvance drilling end of said tubing, said rod having enlarged diameterportions spaced longitudinally thereon Within said tubing, forcing saidenlarged diameter portions into a physical contact with the internalsurface of said tubing, rotating said enlarged diameter portions on thesaid internal surface of said tubing, and rotating said tubing in saidhole being drilled against the surface thereof.

4. A method for drilling a bore hole comprising introducing into thematerial being drilled combined protective and drill tubing of aparamagnetic material, inserting into said drill tubing a drill rodlongitudinally positioned adjacent the advance end of said drill tubing,said drill rod having enlarged diameter disks spaced longitudinally onsaid drill rod within said tubing, forcing said disks into contact Withthe internal surface of said drill tubing with magnetic means, rotatingsaid disks on the internal surface of said drill tubing around the axisof said drill tubing, and rotating said drill tubing in the hole beingdrilled against the surface thereof.

5. A method according to claim 4 in which said drill tubing has slottedportions extending through its lower end and in which the slottedportions are covered by a compressed helical spring surrounding saiddrill tubing, including the step of releasing said spring from itscompressed position so that it will form a filter externally of saidslots.

6. A method for drilling a bore hole comprising introducing into thematerial to be drilled combined protective and drill tubing, inserting adrill rod into said drill tubing, said rod having disks longitudinallyspaced thereon within said tubing, eccentric weights secured on said rodbetween said disks, rotating said rod and Weights so as to force saiddisks to rotate on the internal surface of said drill tubing, androtating said drill tubing against the surface of the hole beingdrilled.

7. A method for drilling a bore hole comprising introducing into thematerial to be drilled combined protective and drill tubing, insertinginto said drill tubing a cylindrical core, inserting a drill rod intosaid core, said rod being eccentric Within said core, rotating said rodand said core so as to force said core to rotate on the internal surfaceof said drill tubing, md rotating said drill tubing against the surfaceof the whole being drilled.

8. A method for drillnig a bore hole comprising introducing protectiveand drill tubing into the material in which the Whole is to be drilled,inserting a drill rod into said drill tubing in a position adjacent thedrilling end of said drill tubing, said rod having eccentric camssecured and spaced thereon, rotating said rod and said cams so as tocause a bending effect in said drill tubing, and rotating said drilltubing against the surface of the hole being drilled.

9. A method for drilling a bore hole comprising introducing protectiveand drill tubing into the material to be drilled, rotating a curvedsubstantially cylindrical rod against the internal surface of saidtubing, said rod being in slip fit Within said tubing, and rotating saiddrill tubing against the surface of the hole being drilled.

References (Cited in the file of this patent UNITED STATES PATENTS102,572 McMillan May 3, 1870 1,166,011 Shaffer Dec. 28, 1915 1,671,136Stokes May 29, 1928 2,229,912 Baily Ian. 28, 1941 2,510,386 Denning etal. June 6, 1950 2,546,806 Wenander Mar. 27, 1951 2,654,586 Berry Oct.6, 1953 2,730,176 Herbold Jan. 10, 1956 2,841,995 Sieber July 8, 1958

